Seal ring for a floating tank roof

ABSTRACT

A seal ring for a floating tank roof where the roof has lateral side walls adjacent the tank walls. The seal includes a pair of rubber strips that can enclose a resilient material. One of the rubber strips forms a loop at its lower portion to receive a pulley cable or tube for positioning the seal.

baited States Patent 1191 Barbier Mar. 5, 1974 SEAL RllNG FOR A FLOATING TANK ROOF [75] Inventor: Claude Barbier, Vesinet, France [73] Assignec: Le .loint Francais, Paris, France [22] Filed: Feb. 28, 1972 121 Appl. No.: 229,874

[30] Foreign Application Priority Data Feb. 26, 1971 France 71.06744 52 us. c1. 220/26 s [51] Int. Cl B65d 87/18 [58] Field of Search 220/26 S, 26 R [56] References Cited UNITED STATES PATENTS 3,426,934 2/1969 Marulic .L 220/26 S 3,434,619 3/1969 Nelson/t. 220/26 5 3,154,213 10 1964 Ulm 220/26 s FOREIGN PATENTS OR APPLICATIONS 9/1963 Great Britain 220/26 S Primary Examiner-George E. Lowrance Assistant Examiner-Steven M. Pollard Attorney, Agent, or FirmSughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT -A seal ring for a floating tank roof where the roof has lateral side walls adjacent the tank walls. The seal includes a pair of rubber strips that can enclose a resilient material. One of the rubber strips forms a loop at its lower portion to receive a pulley cable or tube for positioning the seal.

8 Claims, 3 Drawing Figures PATENTEDHAR 5W axmsm SHEET 2 BF 2 SEAL RING FOR A FLOATING TANK ROOF BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has for its object providing a seal ring for inside floating tank roofs, more particularly in the petroleum industry with a view to storing hydro-carbons, such as oil.

2. Description of the Prior Art In seal rings usually produced for such types of tanks, a liquid, gaseous or spongy packing, enclosed in a flexible covering fixed to the floating roof is generally used. Such a covering, made of a single strip or two strips, presses against the inside wall of the tank and moves vertically along that wall according to the variations in the level of the liquid contained in the tank.

The installing of such a ring is generally effected as follows:

The upper part of the ring can be bolted either on suspension rods which are, themselves, bolted to the upper part of the roof, or on angle irons, themselves fixed by bolting or welding to the-wall of the roof.

The lower part of the ring can be either free or bolted to angle irons themselves fixed to the lateral wall of the roof by bolting or welding, or bolted onto rigid rods fixed or made fast to the fixing means of the upper part of the ring or to the lower part of the floating roof.

The fixing of the lower end of the ring generally sup ports the ring and the packing in their position so that they cannot over-balance duringthe raising and lower ing movements of the floating roof. The fixing of the lower part of the ring by one ofthe rod systems such as mentioned above, makes it possible to provide support for pressing the covering against the lateral wall of the tank. The prior art has provided a number of seals for tanks, such as U.S. Pat. No. 3,055,533, French Pat. No. 1,344,122, British Pat. No. 882,189 and German Pat. No. 1,246,580.

Such seal rings have, however, a certain number of disadvantages. The relatively complex design and structure of such devices for connecting the sealing ring gives rise to excessively long installing and removing periods, more particularly, for fixing the lower part, which is not readily accessible, making maintenance and repair operations on the tanks particularly complicated.

Furthermore, the materials used for such rings have insufficient resistance, with respect to certain hydrocarbons, this leading to a rapid damaging of the ring, especially when relatively volatile petroleum products are stored in the tanks in which they are used. Thus, there exists a need for a relatively simple and efficient sealing ring that is easily installed in a tank.

The present invention enables such disadvantages to be overcome.

SUMMARY OF THE INVENTION The object of the presentinvention is to provide a sealing ring having a particularly simple design and structure, intended more particularly for floating roof hydro-carbon storage tanks, such a ring being very easy to install and remove, while providing perfect fluidtight sealing with respect to the hydro-carbons stored.

The invention, therefore, has for its object to provide a sealing device for a floating tank roof, intended, more particularly, for storing hydro-carbons, of the type comprising a flexible cover containing'a compressible material, fixed to the upper part of the roof and formed by two strips, a first of which presses against the inside wall of the tank, and the second of which presses against the lateral wall of the roof. The second strip being stretched substantially along the lateral wall of the roof has, at the level of the lower part of the roof, a closed loop in which an element intended for pressing the lower part of that second strip against the wall of the floating roof is engaged.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT Thus it is that FIG. 1 shows a storage tank 1 inside which a floating roof 2 is moved vertically according to the fluctuations in the level of the liquid stored (not illustrated). The seal device consists of a flexible covering 3, as an assembly, inside which a compressible material 4, consisting for example, of foam polyurethane,

is arranged. The covering 4 consists, for example, of two strips; a first strip 5 is stretched along the wall of the floating roof 2 and held at its lower part by rolling and welding round a tube 6; the lower end of the strip 5 is folded over then welded to the strip 5 to form a closed loop 15 in which the tube 6 is engaged. A second strip 7 is welded, at its lower part 8, to the strip 5 and presses laterally against the inside wall of the tank 1. Furthermore, the fixing of the upper parts of the two strips described .above on the floating roof 2 is ensured by means of bolts 9, through flat irons 10. Such strips are made of a plastic material, such as, nylon, coated with a covering substance which is inert with respect to hydro-carbons, in this case, polyurethane.

The strip 5, folded back at its lower part to form the loop 15 surrounding the tube 6 and welded at 11 by using a high frequency welding technique, for example, is illustrated. The tube 6, made of plastic material is pressed against the outside wall of the floating roof by means of angle irons 12 having an L-shaped crosssection (FIG. 1) and welded at intervals on the wall of the floating roof. Notches 13 are formed in the lower part of the strip 5, forming the loop 15 opposite the angle irons 12. FIG. 2 also illustrates the lower part of the strip 7 welded to the strip 5, as well ss openings 14 provided in the upper part of the strip 5 and having the screws of the fixing bolts 9 (FIG. 1) fitted in them. The tube 6 has been illustrated with a circular cross-section; it can have a cross-section with a different shape and can also be solid or hollow. I

It can be seen that the installing and removal of the ring are particularly easy. For example, for installing, all that is necessary is to position the tube 6 in the angle irons 12 through the notches 13 of the lower part of the strip and to effect the bolting of its upper part.

In FIG. 3 illustrating a varied embodiment of the invention, the references identical'to those in FIGS. 1 and 2 designate the same elements. This embodiment differs from that the FIG. 1 in that the tube 6 is replaced by a cable 16. The holding of the cable 16 against the lateral wall of the floating roof 2 is effected, moreover, by pulling the cable 16 taut. One of the ends of the cable 16 is fixed by means of a spring 17 to a pulley 18 having a substantially horizontal axis welded to the wall of the roof at its lower part and on an angle iron such as 12. The fixing of the other end of the cable 16 is effectd, after having engaged the cable 16 on the pulley 18 so that it rises along the lateral wall of the roof 2, it being fixed to the upper part of the floating roof 2. This fixing is effected, here, by means of a pulley 19 and a spring 20.

The ring which is the object of the invention can be used in all cases where excellent fluid-tight sealing must be provided between the wall of a tank and a floating roof. It is advantageously implemented in hydro-carbon storage tanks used in the petroleum industry.

It must be understoodthat the invention is in no way limited to the embodiment described and illustrated, which has been given only by way of example. More particularly, without going beyond the scope of the invention, details can be modified, certain arragements can be changed, or certain means can be replacedby equivalent means.

What is claimed is:

1. ln a fluid hydrocarbon storage tank or the like including a vertical cylindrical tank wall and horizontal floating roof transversely spanning the tank interior, said floating roof including an annular lateral wall facing said tank wall, and a sealing ring fixed to said lateral roof wall and contacting said tank wall for sealing said floating roof and said cylindrical tank wall, the improvement wherein: said sealing ring comprises a cover formed by first and second annular strips fixed at their upper edges commonly to said lateral roof wall, said first strip lying flush with said lateral roof wall and terminating in a closed loop at its lower edge, a circular reinforcing element within said loop and extending the full circumference of said lateral roof wall and means fixed to said lateral roof wall at circumferentially spaced locations and engaging said circular reinforcing element to maintain said first strip in contact with said lateral wall, said second strip being welded at its lower edge to said first trip intermediate of the top and bottom edges of said first strip, and a compressible material ring sealably enclosed within a cavity defined by said strip and maintaining said second strip in sealing contact with said vertical tank wall.

2. A storage tank according to claim 1, wherein the loop is formed by folding the lower end of the first strip and welding that edge on the corresponding portion of the first strip.

3. A storage tank according to claimv2, wherein the element consists of a tube.

4. A storage tank according to claim 2, wherein the element consists of a cable.

5. A storage tank according to claim 2, wherein the first strip has, at its lower part, spaced notches interrupting the closed loop, and said means fixed to said lateral roof wall at circumferentially spaced locations engage the circular reinforcing element at said notches.

6. A storage tank according to claim 5, wherein said engaging means comprise angle irons, such that the lower part of the first strip is pressed against the lateral wall of the floating roof by means of the angle irons fixed on the lower part of the lateral wall of the roof and spaced at substantially the same interval as the notches from one another and ovelying said circular reinforcing element at positions exposed by said notches.

7. A storage tank according to claim 4, further including a pulley, the lower part of the first strip is pressed against the lateral wall of the floating roof by means of the pulley whose axis is fixed on the lower part of the lateral wall of the roof thereby providing the tightening of the cable.

8. A storage tank according to claim 7, further including a spring, one of the ends of the cable being fixed by means of the spring on the pulley, and the other end of the cable being engaged on the pulley and rising along the lateral edge of the roof and being fixed on the upper part of the roof.

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1. In a fluid hydrocarbon storage tank or the like including a vertical cylindrical tank wall and horizontal floating roof transversely spanning the tank interior, said floating roof including an annular lateral wall facing said tank wall, and a sealing ring fixed to said lateral roof wall and contacting said tank wall for sealing said floating roof and said cylindrical tank wall, the improvement wherein: said sealing ring comprises a cover formed by first and second annular strips fixed at their upper edges commonly to said lateral roof wall, said first strip lying flush with said lateral roof wall and terminating in a closed loop at its lower edge, a circular reinforcing element within said loop and extending the full circumference of said lateral roof wall and means fixed to said lateral roof wall at circumferentially spaced locations and engaging said circular reinforcing element to maintain said first strip in contact with said lateral wall, said second strip being welded at its lower edge to said first trip intermediate of the top and bottom edges of said first strip, and a compressible material ring sealably enclosed within a cavity defined by said strip and maintaining said second strip in sealing contact with said vertical tank wall.
 2. A storage tank according to claim 1, wherein the loop is formed by folding the lower end of the first strip and welding that edge on the corresponding portion of the first strip.
 3. A storage tank according to claim 2, wherein the element consists of a tube.
 4. A storage tank according to claim 2, wherein the element consists of a cable.
 5. A storage tank according to claim 2, wherein the first strip has, at its lower part, spaced notches interrupting the closed loop, and said means fixed to said lateral roof wall at circumferentially spaced locations engage the circular reinforcing element at said notches.
 6. A storage tank according to claim 5, wherein said engaging means comprise angle irons, such that the lower part of the first strip is pressed against the lateral wall of the floating roof by means of the angle irons fixed on the lower part of the lateral wall of the roof and spaced at substantially the same interval as the notches from one another and ovelying said circular reinforcing element at positions exposed by said notches.
 7. A storage tank according to claim 4, further including a pulley, the lower part of the first strip is pressed against the lateral wall of the floating roof by means of the pulley whose axis is fixed on the lower part of the lateral wall of the roof thereby providing the tightening of the cable.
 8. A storage tank according to claim 7, further including a spring, one of the ends of the cable being fixed by means of the spring on the pulley, and the other end of the cable being engaged on the pulley and rising along the lateral edge of the roof and being fixed on the upper part of the roof. 